This invention is generally directed to a medical alert pendant for use as a wireless remote actuation device in an emergency alarm system or the like. More particularly, the invention contemplates a sealed, waterproof housing construction for a medical alert pendant.
Emergency alarm systems provide monitoring of and response to the needs of elderly or infirmed persons confined to their residences. A medical alert pendant makes emergency care for the person accessible and allows the person to feel comfortable and secure in their home.
The elderly or infirmed person can wear the medical alert pendant on themselves, for example on their wrist, belt, or around their neck, or place it in an easily accessible area. If an emergency occurs, the person depresses a button on the medical alert pendant which activates a transmitter. The transmitter sends a signal to a receiving unit that will then automatically dial a monitoring number. Once the monitoring number receives the signal, they know that an emergency has arisen and they will have pre-assigned instructions as to who they should call, be it, for example, a doctor, fire department or an emergency unit.
Most medical alert pendants are not watertight and therefore cannot be worn or carried by a user in the bathtub or shower. The bathtub or shower is a frequent site of accidental falls and the accessibility of the medical alert pendant is important in summoning help. One example of an attempt to provide a waterproof medical alert pendant can be found in U.S. Pat. No. 4,491,970, which also vents the inner portion of the pendant relative to pressure change.
The medical alert pendant of the type and kind shown in U.S. Pat. No. 4,491,970 is designed to vent the inner portion or chamber of the housing wherein the electrical components are provided. The patent discloses a labyrinth type path to vent the interior of the housing to atmospheric pressure. Other types of vents could be used such as a port in the housing covered by a hydrophobic microporous membrane which would allow air pressure to be vented, yet prevent the entry of moisture. These designs, however, are subject to problems.
More specifically, since air can pass into or out of the housing, so can moisture vapor. Thus, should a negative pressure situation exist inside the housing, air or vapor can be sucked into the interior of the housing. When the air or vapor condenses, moisture will be introduced into the housing which can build up and short-circuit the electrical components within the housing. It should be noted that where a positive pressure exists, there is no danger that air or water vapor will be sucked or drawn into the interior of the pendant housing.
The present invention presents a novel medical alert pendant and housing structure that is intended to overcome this problem as well as to present several other advantages and improvements.
More specifically, the pendant housing construction of the present invention provides a sealed interface between the housing halves, which provides a primary seal. Also, a secondary seal is provided by the enlarged button portion of the sealing membrane being sealed to the aperture in the housing. Further, the membrane, as discussed hereinafter, is designed to accommodate negative pressure situations which tend to draw air or water vapor into the housing, that is where the pressure inside the housing is less than ambient. In this regard, as discussed hereinafter, the membrane includes a web portion that can flex or deform inwardly under negative pressure conditions, this flexing will decrease the chamber volume and precludes any tendency to draw or suck air or water vapor into the housing across the primary seal at the housing juncture.